How do you mean exactly? With the MX518, in Counter-Strike at least, I was able to configure all my buttons fine.

For instance, I use the forward button to bring up the buy menu, and the back button to enable voice chat. The only Logitech mouse I know by experience that is hard to configure for gaming is the MX1000.

Unless there is another way, my games do not natively recognize anything other than the first 3 primary buttons on my MX700.

The side buttons, I can only use if I pre map them to "letter" binds, and then set those letters to specific actions in the game.

It goes like this:

I config my side buttons for a specific function, they should appear as MOUSE4 and MOUSE5... but they won't. I have to go into the Logitech software, configure my MOUSE4 = "P" and MOUSE5 = "O" or something else like that. Then, when I go into the game, I have to set the action that I want for MOUSE4, I hit it to the binded key "P", and so on.

Well, the only thing I can figure, is that it could do with the drivers.

I believe the MX700 uses MouseWare, which I believe to be junk anyways. You may want to try the drivers they send with their newer mice, although I cannot guarentee they will work, but I don't see why they wouldn't.

You can download the latest one here, and hopefully that will work as hoped.

Don't worry about the MX518 pic.. it should be a universal driver. They just don't edit the older mice pages with new drivers :|

Logitech Cordless Combo (Mouse & Keyboard) Elite. They don't seem to make them any more or at least they're not on their web site. I need to upgrade my drivers... the cordless works fine for all gaming for me.